1. Field of the Invention
Aspects of the present invention relate to an audio reproduction apparatus, and more particularly, to a bass enhancing apparatus and method for enhancing bass by generating harmonics of the bass when a signal is reproduced using a miniaturized speaker.
2. Description of the Related Art
In common, audio data reproduced by a multimedia reproduction device, such as a Compact Disc (CD) player or a Digital Versatile Disc (DVD) player, is reproduced by a speaker. A user hears a sound output from the speaker. In this case, how faithfully an original sound is represented depends on the performance of the speaker and audio processing technology of the multimedia reproduction device. Meanwhile, according to the development of the audio processing technology, speakers are miniaturized. However, as the size of a speaker is smaller, it is limited to faithfully reproduce a bass sound.
Thus, a bass enhancing apparatus enhances a bass component, which is easy to be insufficient when an audio signal is reproduced using a miniaturized speaker.
A technique related to the bass enhancing apparatus is disclosed in a United States Patent Application Publication of Aarts, US 2005/0013446 (filed 12 Aug. 2004 entitled Audio System), and a United States Patent Application Publication of Manish et al., US 2005/0265561 (filed 9 May 2005 entitled Method and Apparatus to Generate Harmonics in Speaker Reproducing System).
FIG. 1 illustrates an embodiment of a conventional bass enhancing apparatus according to Aarts. Referring to FIG. 1, a signal received via an input terminal 91 is input to a bass component extractor 92. The bass component extractor 92 extracts a component belonging to bass in the input signal which cannot be reproduced. A harmonics generator 93 generates a second harmonic, a third harmonic through to an nth harmonic of the extracted bass component. An adder 96 adds the harmonics to the input signal and outputs the adding result to an output terminal 97.
An integer harmonics generation method can be implemented, for example, using a rectifier, an integrator, and a resetting circuit as illustrated in Manish et al.
However, the conventional bass enhancing apparatus generates harmonics by synthesizing signals having a fixed gain. Thus, when the conventional bass enhancing apparatus reproduces a signal having an excessive amplitude in the bass register through a miniaturized speaker, the dynamic range of which is limited by the size thereof, the signal is distorted.